With the growing interest in the treatment of thromboembolism with lytic agents such as urokinase and sureptokinase, there has arisen a need for substantially automated means for measuring the lysis time of a preformed plasma (or fibrinogen) clot with more precision then has been heretofore available. Typical of previously available apparatus for this general purpose is the device disclosed in U.S. Pat. No. 3,605,010 to S. G. Folus, and also that disclosed in the publication of S. G. Folus and D. N. Kramer, entitled "A New Electromechanical Device for Measurement of Clot Lysis Times", Am. J. Clin. Path. 54: 361-368, 1970. Due to the relative complexity of the apparatus disclosed in these publications, it is not easy to obtain satisfactory operation thereof, and the apparatus includes numerous sources of error. It is preferable to perform the lysing time measurement in a simpler and more reliable manner. Various other procedures and devices have been developed in the past, relating to such time measurement, for example, as described in A. P. Fletcher, "The Measurement of the Components of the Plasminogen-Plasmin System in Biological Fluids", Biochem. J. 56; 677-682, 1954, and J. Plough et al, "Urokinase, An Activator of Plasminogen from Human Urine. I. Isolation and Properties", Biochem. Biophys. Acta, 24; 278-289, 1957. These further-described procedures and devices likewise fall short of filling the above-defined need.
A preliminary search of the patented prior art reveals the following prior U.S. patents of interest: Nos
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